In my experience, backwards compatibility is a myth:
PS3, no chance - I was too late getting a PS3 so got the rape version with no BC.
360, HA! - Ok if you only want to play a handful of classic games, don't for one instant think that any old XBox game will work.
I don't rely on it and never will - console manufacturer's don't want us to play old disks, they want us to go ''ohh, I remember that game, in fact I still have it, given that I supported these consoles in the early days and have a handsome collection of disks. I want to play it again, so I'll go an buy it all over again, because they deserve to be paid twice for some reason known only to them... it's great because any royalty agreements will be void or expired, so all that money goes to the copyright holder, not the talent that created the games we love.''
I rely on emulation and the App store for my nostalgia fix - if you have a handsome collection of games for a system, keep the system! - if it dies, replace it!. I think it's better to accept your fate as a gamer, make space for old consoles, buy a shelf unit and have them all sitting on that - tell the girlfriend/wife/partner to get over it and accept the jungle of cables in that corner - or take over the basement. It's the only way to keep your stuff these days - that or pay for it all over again, again, again, again.
It would be nice if the manufacturer's recognized hardcore gamers and collectors - and made a collectors edition of consoles, massive hard drives, backwards compatibility, maybe even some extra features like built in Action Replay, emulation, BC options like smoothing the screen or adding scanlines for authenticity. Now, that would make me sit up and take notice of these next gen consoles. Currently, I couldn't give a single solitary f... about them - I've taken to PC gaming because of the retardation of the console market... by that I mean Kinect of course.